This invention relates to cephalosporin antibiotic compounds. In particular, it relates to cephalosporin compounds substituted in the 2-position with a vinyl halide group referred to herein as a 2-helomethylidene group.
Cephalosporins substituted in the 2-position of the six-membered dihydrothiazine ring have been previously described. 2-Methyl and 2-methylenecephalosporin compounds are described by I. G. Wright et al., J. Med. Chem. 1971, 14, 420-425. G. V. Kaiser, et al. ibid 426-429, described 2-thiomethyl and 2-thiomethylene cephalosporin compounds which are obtained by the addition of mercaptans to the 2-exomethylenecephalosporin sulfoxides described by Wright. Dolfini, U.S. Pat. No. 3,852,282, teaches cephalosporins substituted in the 2-position by halogen, lower alkoxy, lower alkenyloxy, lower alkynyloxy, aryloxy, lower alkanoyloxy, lower alkylthio, lower alkenylthio, lower alkynylthio, arylthio, aroylthia or alkanoylthia.